Process for the production of composite safety glass

ABSTRACT

An improvement in a method for manufacturing a composite safety glass wherein one or more silicate glass panes is bonded to a plasticized synthetic resin film at an elevated temperature, the improvement residing in employing as the plasticized synthetic resin film a soft film of a polymer of ethylene and/or propylene and effecting the bonding under pressure at a temperature of at least 120° C. and up to 200° C.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 114,180, filed 10-28-87,now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the production of composite safety glass byunilateral or bilateral bonding of one of more silicate glass panes to aplasticized soft film of an ethylene or propylene mono-, co- orterpolymer. More especially, this invention is directed to themanufacture of laminated safety glass by the bonding together of one ormore sheets of silicate glass to a soft film of a polymer of ethylene orpropylene.

2. Discussions of the Prior Art

There are many applications for laminated safety glass. It is used, forexample, in the building industry for the production of doors orwindows, bullet-proof glass and skylights, and in the automotiveindustry especially for the manufacture of windshields.

The term "laminated safety glass", as used herein, is to be understoodto means a sandwich consisting of one or more silicate glass sheetsbonded together in one unit with a film of organic material. If theglass is broken, the fragments adhere to the film. Loose, sharp-edgedsplinters are not formed (cf. DIN 1259, Sheet 2).

Laminated safety glass must satisfy certain quality requirementsaccording to the purpose for which it is to be used. In the case ofmotor vehicles, these quality requirements are laid down in the"Strassenverkehrszulassungsordnung" of the German Federal Republic,Section 22, No. 29, in "Motor Vehicle Safety Standards" Nos. 205 and208, and in U.S.A. Standard Z 26.1-1966. Quality requirements for use inthe building industry are established in "American National StandardInstitute" Standard Z 97.1-1966, and for use as bullet-proof materialthey are specified in "Underwriters Laboratories" Standard 752.

In practice, the use of laminated safety glasses on the basis ofsilicate glass sheets bonded together with films of plasticizedpolyvinyl butyral has become widespread. However, the use of polyvinylbutyral films containing plasticizers makes the production of laminatedsafety glass very expensive.

Polyvinyl butyral films cannot generally be manufactured on the commonlyavailable equipment such as is used for the production of other plasticfilms, and apparatus especially designed for this type of film must beused not only for the production of such films, but also for theirincorporation into laminated safety glass. Certain special requirementsmust be satisfied. For example, the films have to be adjusted to certainspecific moisture contents and to precise free hydroxyl group contentsin order that the optimum adhesive strength desired for the particularapplication can be consistently achieved. On account of theirsensitivity to moisture, polyvinyl butyral films must be handled undercontrolled atmospheric conditions in most cases, not only during theirmanufacture and storage, but also immediately prior to theirincorporation into the laminated safety glass. It is alsodisadvantageous that polyvinyl butyral film containing plasticizersticks to itself and therefore must first be provided with a partingmeans if they are to be stored or transported in the form of stacks ofdie-cut blanks or in the form of rolls.

It has been proposed to replace the plasticized polyvinyl butyral filmwith other organic adhesive materials. For example, it is proposed inGerman No. "Offenlegungsschrift" 1,421,142 that films of highlypolymerized vinyl chloride be used as fire-retardant intermediatelayers, to which vinyl chloride of a low degree of polymerization (Kvalues under 50, preferably between 30 and 40) has been added for theachievement of adhesion to glass. The low polymers can also be appliedto the surfaces of the glass sheets in the form of a thin, viscidcoating before they are joined together. With adhesive films of thiskind, approximately the same problems are encountered as in thepreparation and use of polyvinyl butyral films.

In co-pending application Ser. No. 738,402, the disclosure of which ishereby incorporated by reference, it is proposed to obviate theafore-mentioned problems by employing as the film to which the silicateglass layers are bonded a plasticized polyvinyl chloride film. It hasbeen discovered, in accordance with our invention as disclosed therein,that improved adhesion and shatter resistance are provided using aplasticized polyvinyl chloride film. The strength of adhesion isremarkably superior, according to the procedure therein, than has beenobtained heretofore for composite safety glasses utilizing polyvinylbutyral. It has become desirable, however, to provide other forms ofcomposite safety glass employing films other than those containingpolyvinyl chloride. It has become particularly desirable to providecomposite safety glass which is not only useful in the vehicle sector,but can be used in the construction sector as well for window panes,bullet-proof glass, window railings, partitions and the like. It hasbecome especially desirable to provide such laminated safety glass whichcan take advantage of the properties of other synthetic resin films.

SUMMARY OF THE INVENTION

In accordance with the invention, there is now provided a furtherimprovement in a method for manufacturing a laminated safety glasswherein at least one silicate glass sheet is bonded to a side of aplasticized synthetic resin film at an elevated temperature, theimprovement residing in employing as the plasticized synthetic resinfilm a plasticized soft film of an ethylene or propylene polymer such asan ethylene or propylene homo-, co- or terpolymer.

Preferably, the soft films of this invention have a Shore A hardnessvalue, as measured by Deutsche Industrie Norm (DIN) 53 505 of 40-98,more especially 50-95.

The ethylene and/or propylene copolymers generally have a molecularweight between 20,000 and 100,000, preferably between 30,000 and 60,000,the molecular weight being the number average molecular weightdetermined in o-dichloro benzene at 90° C. in a membrane osmometer. Themelt flow index of the ethylene and/or propylene copolymers has valuesbetween 0.1 and 20 g/10 minutes determined according to DIN 53735.

The manufacture of films, according to this invention, having thedesired Shore A hardness values is, per se, known. The manufacturingprocess is generally conducted with the aid of comonomers which are tobe incorporated by polymerization and which behave as plasticizers.

Vinyl acetate can be mentioned, for example, as a plasticizingcomonomer. Such copolymers of ethylene or propylene have the advantageover the plasticizer-containing, partially acetalized, polyvinyl alcoholfilms heretofore used as adhesive films between glass panes in that theyexhibit a substantially greater low-temperature resistance under impactload.

Other suitable comonomers for producing the ethylene or propylene co- orterpolymers, etc., are olefinically unsaturated compounds, such as, forexample, ethylene, propylene, butadiene, vinyl ethers, vinyl chloride,vinyl fluoride, acrylic acid, acrylic acid esters, e.g., ethyl acrylate,butyl acrylate, maleic anhydride, maleic acid esters, styrene, and thelike, individually or in a mixture with one another.

One can also use the reaction products of these co- or terpolymers,produced, for example, by saponification reactions or neutralizationreactions with metallic ions.

Mixtures of ethylene homopolymers or propylene homopolymers withethylene copolymers or propylene copolymers and/or ethylene terpolymersor propylene terpolymers are also usable for the production of the filmsaccording to this invention.

The term "polymers of ethylene and/or of propylene" also includesmixtures wherein the polymer component consists of more than 50 percentby weight of the above-mentioned homopolymers and/or copolymers and/orterpolymers and, up to 100 percent by weight of the remainder, of othersynthetic resins compatible with the aforementioned olefinic polymers.

For the plasticizing of such mixtures, one can use conventionalplasticizers compatible with these polymers or polymer mixtures.

Clear-transparent films are preferred although, depending on theintended purpose of using the composite safety glass articles, it isalso feasible to employ opaque films.

The following silanes can be utilized in accordance with the invention:

(a) Silanes or silane mixtures which increase the adhesive stength atthe bond; and/or

(b) Silanes or silane mixtures which reduce the adhesive strength.

In general, silicon-organofunctional silanes effect an increase in thebond strength, whereas generally silicon-functional silanes lower thebond strength.

Silicon-functional silanes are understood to mean those wherein thefunctional groups, such as, for example, halogen or alkoxy groups, arelinked directly to the Si atom. Such groups are, in general, readilyhydrolyzed.

Silicon-organofunctional silanes are difunctional. In addition to atleast one hydrolyzable group which is to react within the composite withthe glass surface, there must be present at least one functional groupwhich is bound to the silicon by way of one or more carbon atoms andwhich is reactive, for example due to amino or epoxy groups or due todouble bonds.

Silicon-organofunctional silanes suitable along the lines of the presentinvention are, for example, those of the general Formula I ##STR1##wherein R represents a hydrolyzable residue, such as Cl, OR" (R"=a C₁₋₈alkyl residue, preferably of 1-4 carbon atoms, optionally containinghetero atoms, such as --O-- or --S--, or an acyl residue),

R' represents an alkyl residue of 1-18 carbon atoms,

A represents a bivalent alkylene residue of 1-10 carbon atoms,preferably 2-6 carbon atoms, which can optionally be branched, and

Z represents a residue containing a functional group, wherein thefunctional group can be, for example ##STR2## wherein R² is H or aminoalkyl of 2-8 carbon atoms in the alkyl residue; and R³ is H or R² ; andR⁴ is H or CH₃ or C₂ H₅ ; and n is 1 to 3, and p is 0 or 1.

Suitable aminosilanes are, for example, those of the Formula II

    NH.sub.2 --(CH.sub.2).sub.n --Si--(OR).sub.3               II

wherein

n is 2 to 6 and

R is C₁₋₈ alkyl (branched or unbranched and optionally interrupted by Oatoms, such as, for example, the --CH₂ --CH₂ --O--CH₃ residue).

Examples in this connection are γ-aminopropyl and -ethyltrialkoxysilaneswherein the hydrogen atoms of the amino group can optionally besubstituted by an amino or polyamino alkyl residue (for example theresidue [--CH₂ (CH₂ NHCH₂)_(x) CH₂ --]NH₂, x=1 to 8).

Also suitable are β-aminoethyl-γ-hydroxypropylmethyldialkoxysilanes orpolyaminotrialkoxysilanes, for instance [(CH₃ O)₃ Si--(CH)₂ ]--NH--CH₂--(CH₂ NHCH₂)_(x) --CH₂ NH₂ (x=1 to 8).

Suitable iminosilanes are, for example, those of the Formula III

    HN[CH.sub.2 --CH.sub.2 --CH.sub.2 --Si(OR).sub.3 ].sub.2   III

wherein R has the same meanings as indicated in Formula II.

Especially worth mentioning are the γ-imidazolylpropyltrialkoxysilanesas described, for example, in DOS German Offenlegungsschrift No.2,420,801, primarily γ-imidazolylpropyltriethoxysilane.

In the silanes containing epoxy groups, the epoxy group ##STR3## islinked to the alkylene silyl residue either by way of an ether group(--CH₂ --O--) or by way of an ester group ##STR4## However, it is alsopossible that the epoxy group is linked directly or via a cycloaliphaticring with the alkylene residue, or that the epoxy group is part of sucha cycloaliphatic residue. The production of such silanes has beendescribed in German Patent No. 1,061,321. The epoxy-group-containingsilanes mentioned in this reference can likewise be used in accordancewith this invention. Especially suitable silanes, containing etherbridges, are the glycidyloxypropyltrimethoxy-or -triethoxysilanes.

Among the epoxysilanes which contain ester bridges, worth mentioning isthe compound ##STR5##

A suitable epoxysilane wherein the epoxy group is part of acycloaliphatic ring is β-3,4-epoxycyclohexylethyltrimethoxysilane.

Among the aforementioned compounds, preferred silicon-organofunctionalsilanes which increase the bond strength areγ-imidazolypropyltriethoxysilane andγ-glycidyloxypropyltrimethoxysilane.

The silicon-organofunctional silanes with unsaturated --C═C-- bonds,such as, for example, silanes which contain vinyl, propenyl, acryl,methacryl groups, which can be utilized in accordance with thisinvention, effect an increase in the bond strength only if they are usedtogether with radical-forming agents. Without the addition of aradical-forming agent, the adhesive strength does not only remain thesame, i.e. without any increase, but is even lowered to a minor extent.

Suitable radical-forming compounds are those customarily employed in theradical polymerization of olefinically unsaturated compounds, preferablyperoxides, such as dicumyl peroxide.

The radical-forming agents are generally utilized in amounts of 0.01-1%by weight, preferably 0.01-0.5% by weight, based on the solvent or thevarnish set forth below. Examples for these silanes arevinyltrialkoxysilanes, such as, for example, vinyltrimethoxysilane,vinyltriethoxysilane, γ-methacryloxypropyltrialkoxysilanes, especiallythe -trimethoxy- or -triethoxysilane, vinyl[tris-β-methoxy]ethoxysilane,vinyltriacctoxysilane, and the like.

In case of a composite safety glass wherein a very firm adhesion isdesired between the silicate glass and the soft film, onlysilicon-organofunctional silanes are utilized according to thisinvention.

Such composite safety glasses with very good adhesion can be utilized,inter alia, in the construction sector, for example as window panes,bulletproof glass, or in window railings or partitions.

Composite safety glass having a specific adhesion within a medium rangeof the adhesion scale is used in the vehicle sector, for example, asglazing in automotive vehicles, rail vehicles, agricultural vehicles,ships, airplanes, etc.

In these fields of application, the adhesive strength adapted to therespective utilization can be provided by varying the type of silane andthe quantity thereof. In this connection, it is, of course, necessary toconsider also the adhesive strength of the respectively utilized, softsynthetic resin film which is not treated with the silane.

The bond strength of a glass pane bonded to a soft film of a polymer ofethylene and/or propylene in accordance with the invention is measuredby the so-called "pummel adhesion value". The test to determine thepummel adhesion value is described in British No. 1,093,864. Inaccordance with the test, a test specimen, measuring approximately150×300 mm, is refrigerated for about 2 to 8 hours at -18° C.±0.5° C.,laid on a metal block tilted at an angle of about 45°, and hammered witha flat-faced hammer until the silicate glass is pulverized. The testsurface size is about 100×150 mm. Adhesion is judged according to ascale from 0 to 10. These values are as follows:

    ______________________________________                                        % exposed film surface                                                                          Pummel value                                                ______________________________________                                        100               0                                                           95                1                                                           90                2                                                           85                3                                                           60                4                                                           40                5                                                           20                6                                                           10                7                                                            5                8                                                            2                9                                                            0                10                                                          ______________________________________                                    

Visual judgment is facilitated by the fact that illustrations are alsoprovided on the scale opposite the pummel values. It has been found thatthis "non-quantitative" pummel test is entirely adequate in practice,and that adhesion can be judged with sufficient accuracy on the basis onvisual appraisal.

In the examples that follow, the pummel adhesion value was determined at-20° C., +23° C. and +90° C.

By a combination of silanes increasing the bond strength and silanesdiminishing the bond strength, one can, for example, provide a quitespecific adhesive strength.

If the adhesive strength of a film, which is not treated with thesilane, is too high for a certain purpose of use, then one can, forexample, employ a silane or silane mixture to reduce the bond strengthas the sole silane component, for example a silicon-functional silane orsilane mixture.

According to the invention, silicon-functional silanes utilized hereinare those of the general formula R'_(n) --Si--R_(4-n') wherein R'represents identical or different, saturated, optionally branched alkylresidues of 1-18 carbon atoms, R represents halogen, preferably Cl, oridentical or different saturated alkoxy groups of 1-8 carbon atomsoptionally interrupted by hetero atoms, such as --O-- or --S--, or anacyl residue linked to the Si atom via an oxygen atom, and wherein n is1 to 3, n=1 being preferred.

Examples in this connection are the following: propyltriethoxysilane,propyltrimethoxysilane, isopropyldimethoxysilane, n-butyl- orisobutyltriethoxy- or -trimethoxysilane, isobutyltriacetoxysilane, andthe like.

An advantageous embodiment of the process according to the inventionresidues in utilizing the silanes or silane mixtures dissolved insolvents, and to apply the thus-obtained solution by dipping, spraying,or similar simple methods to at least one of the respective boundarysurfaces. After application, the solvents are removed before theindividual layers are bonded together. This mode of operation can alsobe used according to this invention with the use of polyvinyl butyralfilms as the synthetic resin films.

It has been known from German Auslegeschrift (DAS) No. 2,410,153, tocontrol the bond strength between plasticizer-containing, partiallyacetalized polyvinyl alcohol films and inorganic glasses by adding tothe partially acetalized resin predetermined quantities of a silanebefore or during processing into a film. In this mode of operation, thesilane is admixed to the resin in a separate process step; the silane isuniformly distributed throughout the entire resin. Thus, in this method,relatively large amounts of the silane are utilized.

It has now been found that even with the use of polyvinyl butyral films,at least an equally satisfactory effect is achieved by treating only thesurface of the layers to be bonded with the silane, this treatment beingconducted with the treating agent in the form of a solution.

In the case of partially acetalized polyvinyl alcohol films, thesolution generally contains both a silicon-functional silane and anorgano-functional silane. However, silicon-functional silanes can beused alone where lower pummel values are satisfactory, e.g., pummelvalues between 2 and 5. It is possible in this way to employconsiderably lower amounts of silane than necessary in the processaccording to DAS No. 2,410,153.

The procedure of applying the silane in a solution to one of theboundary surfaces is especially advantageous where the film is apolyvinyl butyral film. The treatment reduces the effect of the watercontent of the plasticized polyvinyl butyral film on the desiredadhesion to the glass so that it becomes practically insignificant. Itis known that the adhesion of polyvinyl butyral films to glass becomesthe lower, the higher their water content. In contrast thereto, theadhesion increases when the water content is reduced. By treating thesurfaces of the polyvinyl butyral films with solutions ofbond-strength-raising silanes, a constant adhesion value is attainedover a wide range up to high water contents. Conversely, by a treatmentwith bond-strength-reducing silanes, a constant adhesion value isattained over a wide range down to low water contents.

It is furthermore known that plasticized polyvinyl butyral filmsgenerally exhibit a very high adhesion to glass, as desirable in theconstruction field, for example when the glass is used as structuralwindow panes. In case of composite safety panes utilized as windshieldsin automotive vehicles, however, the bond strength displayed by the filmwith respect to the glass must be adjusted to a reduced value in acontrolled fashion. For, if the adhesion is very strong and the pane isdestroyed by an impact force, a penetration in the center of impact willoccur without a large amount of glass being shattered. In case of verypoor adhesion, the cause of impact, for example a falling body, will beelastically absorbed by the film, but the shattering effect is veryhigh. In case of a direct collision with destruction of the windshieldby the impact of a person's head, the film, on the other hand, is togradually dissipate the kinetic energy by stretching. However, on theother hand, the destroyed glass is still to adhere sufficiently to thefilm that dangerous injuries by cuts are avoided. For this reason, theadhesive strength must be set in these cases optimally to a definitepummel adhesion value, which generally ranges between 2 and 5.

According to the invention, the silanes are used in solvents whereinthey are readily soluble and which can be easily evaporated after thefilm treatment. Furthermore, the solvents must satisfactorily wet theplasticized synthetic resin films without dissolving same. Suchproperties are exhibited, for example, by aromatic hydrocarbons, such astoluene or xylene, light petroleum ethers, or also lower alkyl esters oflower aliphatic carboxylic acids, e.g., ethyl or butyl acetate.

The silane concentration in the solutions is 0.0001 to 10 percent byweight, preferably 0.0005 to 7.0 percent by weight, based on thesolvent. The silicon-organofunctional silanes are generally utilized inamounts of 0.01 to 2 percent by weight, preferably 0.05 to 1.0 percentby weight. With the use of polyvinyl butyral films as the syntheticresin films, the concentration is preferably between 0.0005 to 5.0 partsby weight, based on 100 parts by weight of solvent. Thesilicon-functional silanes are generally employed in amounts of 1 to 10percent by weight, preferably 2 to 7 percent by weight.

An advantageous way of using the silane is to dissolve or disperse thesilane in a varnish. This form of utilization is also suitable,according to the invention, with the use of polyvinyl butyral films orpolyvinyl chloride-containing films as the synthetic resin films.

As disclosed in co-pending application Ser. No. 738,402, suitablelacquer or varnish binding agents include non-hardening polymethacrylicor polyacrylic acid esters, soluble non-reactive polyurethanes,postchlorinated polyvinyl chloride, copolymers of vinyl chloride-vinylacetate-vinyl alcohol or of vinyl chloride-vinyl isobutyl ether. All ofthese binding agents are commercial products which are offered byvarious manufacturers as lacquer raw materials. This list is by no meanscomprehensive of all applicable bonding agents.

In addition to the materials set forth in co-pending application Ser.No. 738,402, other suitable varnish materials are those containing inthe varnish binder proportions with free OH-- and/or COOH-- groups. Thisimproved effect is especially apparent with the use of silanes whichcontain epoxy groups.

Co-pending application Ser. No. 738,402 discloses, as a lacquer orvarnish binder having a reactive group, the partially saponifiedcopolymer of vinyl chloride-vinyl acetate. Supplemental examples in thisconnection are also the following copolymers: vinylchloride-hydroxyalkyl acrylate or vinyl chloride-vinylacetate-unsaturated carboxylic acids (for example maleic, acrylic, ormethacrylic acid), or vinyl chloride-unsaturated carboxylic acid alkylester-unsaturated carboxylic acids.

Since reactive groups, especially the COOH-- group, affect lightstability and thermostability, such copolymers consisting of differentmonomers are advantageously combined with other, inert binders, aprerequisite being that the latter are compatible with the reactivecopolymers.

As supplemental examples for inert binders, worth mentioning arecopolymers of vinyl chloride-vinyl acetate or vinyl chloride-carboxylicacid alkyl esters, or chlorinated natural or synthetic rubbers.

Among the nonvolatile components of the silane-containing varnishes are,besides the reactive and/or inert polymers, also plasticizers,stabilizers, and other auxiliary agents. The plasticizers used aredependent, with respect to type and amount, on the plasticized syntheticresin films. The total of nonvolatile components of thesilane-containing varnish is between 1.0 and 20.0% by weight, preferablybetween 2.0 and 15.0% by weight.

Suitable volatile components in the varnishes are, as well-known tothose skilled in the art, organic solvents or solvent mixtures whereinthe nonvolatile components can be dissolved as a clear solution andleave clear films after evaporation. The proportion of plasticizer canrange between 10 and 65 parts by weight, based on 100 parts by weight ofpolymer.

An especially advantageous binder when using polyvinyl butyral films asthe synthetic resin films is plasticized polyvinyl butyral correspondingadvantageously to the recipe of the plasticized polyvinyl butyral filmemployed. However, in principle, the other above-mentioned, film-formingbinders are likewise usable, wherein it is of advantage if these containfree OH-- or COOH--groups.

The silane concentration in the varnishes is 0.0001 to 7 percent byweight, preferably 0.0005 to 5 percent by weight, based on the varnishcomposition. The silicon-organofunctional silanes are generally utilizedin amounts of 0.0001 to 5 percent by weight, preferably 0.0005 to 2percent by weight. The silicon-functional silanes are generally used inquantities of 0.5 to 7% by weight, preferably 1 to 5% by weight. Withthe use of polyvinyl butyral films as the synthetic resin films, thesilane concentrations range between 0.0001 and 2.0 parts by weight,preferably 0.0005 and 1.0 part by weight, based on the silane-containingvarnish.

With the use of silanes containing epoxy groups, the silanes arecontained in the varnish in amounts of 0.01-5% by weight, preferably0.01-2% by weight. Silanes containing amino groups are utilized inamounts of 0.0001-2% by weight, preferably 0.0005-1% by weight.

The use of the silanes in a varnish of polymers of the above-mentionedgroups also makes it possible to specifically set a desired adhesionvalue in the middle zone of the adhesion scale. If there are no OH orCOOH--groups in the binder, a silicon-organofunctional silane whichcontains epoxy groups practically does not at all affect the pummeladhesion value. However, as soon as the binder contains small amounts ofa polymer with hydroxy or carboxy groups, the pummel adhesion value isincreased by a silicon-organofunctional silane with epoxy groupscontained in the varnish. With a constant amount of silane in thevarnish, one can obtain a definite and desired adhesion value by varyingthe relative quantity of inert binders to reactive binders. The use of asilane, especially an organofunctional silane, in a varnish for bondingpartially acetalized polyvinyl alcohol, e.g., polyvinyl butyral, is alsocontemplated especially where lower pummel values are sufficient.

One practical method of effecting the process of this invention residesin applying the silane solution to at least one of the respectiveboundary surfaces of the individual layers, for example, by passing theplasticized synthetic resin films directly from a reel through thesolution wherein the silane is present in a predetermined concentrationand, thereafter, evaporating the solvent. The thus-treated film is nottacky and can be handled in the same way as untreated film.

Furthermore, one can treat the silicate glass panes, instead of thefilms, in the same or a similar manner. However, after the evaporationof the solvent, the silane will be present on the silicate surface as amoist film. In this case, the silane can be baked in, if desired, bymeans of a suitable heat treatment.

However, advantageously, the procedure in this case is to use a silane,dissolved in a solvent, together with a varnish binder. Thesilane-containing varnish is thinly applied to the silicate glasssurfaces, either on one side or on both sides, for example by dipping,spraying, painting or the like, whereby during the subsequent drying ofthis varnish, an organophilic silicate glass surface is produced. Thevarnish can be applied continuously, for example by spraying, applyingwith a doctor blade, or printing. It can be subsequently dried in acontinuous-type tunnel oven.

One can also apply the silane-containing varnish to the synthetic resinfilm used according to this invention. The application step can beconducted as in case of the solvent-diluted silanes, for example,continuously by means of a dip bath or by spraying or with a doctorblade, whereupon the film is squeezed between rolls and then dried in atunnel oven. After application of the silane solutions or of thesilane-containing varnish to the surface of one of the layers to bebonded together and after the solvent has been removed, the films to bebonded are superimposed in the desired sequence and optionally exposedto a preliminary bonding step, if desired, at an elevated temperature ina conventional manner, the laminate being suitably vented during thisprocedure. Thereafter, this preliminary bond is finally bonded under theeffects of temperature and pressure, for example in an autoclave underpressures of about 2-20 kp./cm², preferable 8-15 kp./cm², andtemperatures of between 120° C. and 170° C.

The silanes usable according to this invention are particularly suitablein the production of composite safety glass articles employingsurface-refined silicate glass panes.

The suitable silanes are generally selected in correspondence with thechemical structure of the uppermost layer on the surface-refinedsilicate glass panes, considering the bond strength of the film to beutilized, as well as optionally also considering the varnish employed.

Preferred composite glass articles according to the invention compriseat least one layer of a soft or plasticized plastic film, treated inaccordance with the invention, as the synthetic resin film. They can bemanufactured with uncured, cured, planar, curved, vapor-deposited,imprinted, colored, etched, texturized silicate plate glass optionallycontaining a wire insert, as well as with colorless, colorfullytransparent, colorfully opaque, imprinted, plasticized or soft plasticfilm treated according to the invention, optionally containing insertedwires, wire mesh, fabrics, or articles, such as, for example, solarcells.

The thicknesses of the silicate glasses and/or of the plasticized orsoft plastic films treated in accordance with this invention can beselected to be variable depending on the purpose for which they areused. The number of individual layers of the composite article islikewise selectable as desired. This makes the article useful in theconstruction field in connection with doors and door systems, in windowsand window constructions, in parapets for railings, balconies, orfacades, in partitions as room dividers, balcony partitions, or lotenclosures, in connection with roofs or roof components of terraces,skylights, or greenhouses, in telephone booth or computer systemenclosures, display cabinets, cashier's cages, prisons, or roomsendangered by explosion or implosion, in each case as safety glass forprotection against penetration, break-in, shelling, fire, sound, cold,warmth, heat, optionally with alarm or heating wires, respectively.

In the vehicle sector, the articles can be used as window material inautomotive vehicles, rail vehicles, ships, and airplanes in windshields,rear windows, or side windows, doors, partitions, etc.

It is also contemplated to produce, with the plasticized or soft plasticfilms treated according to this invention, a composite product incombination with other transparent synthetic resins. Thus, visualstructures can be created, for example, using in addition to silicateglass and plasticized or soft plastic film, as viscoelastic materials,polymethyl methacrylate, polycarbonate, polyethylene terephthalate, hardPVC, polyamide, and others, and as soft-elastic, tacky materials,polyurethanes, copolymers of ethylene, polyamides, polyepoxides,polysiloxanes, polymethacrylates, and others.

In order to more fully illustrate the invention by way of specificembodiments, the following examples are presented:

EXAMPLES 1-14

With the use of various copolymers of ethylene and vinyl acetate, filmshaving a thickness of 0.4 mm. were produced and treated by dipping withsilane solutions.

Toluene was chosen as the solvent; this compound is capable ofevaporation before the films treated therewith are further processed.The films were then placed between two glass plates; to remove airbubbles, the sandwich was then passed at room temperature through a pairof rubber rolls and thereafter treated in an autoclave at 12 bar and170° C. for 1.5 hours so that a flawless composite glass was obtained.The glass adhesion of the films was determined according to the pummeladhesion test method at -20° C., +23° C., +90° C.

    __________________________________________________________________________    Ex- Viny1  Silane Dicumyl                                                                              Pummel Adhesion                                      ample                                                                             Acetate                                                                              % by   Per-   Value at                                             No. Content                                                                              Weight oxide  -20° C.                                                                     +23° C.                                                                     +90° C.                             __________________________________________________________________________    1   8% by Wt..sup.(1)                                                                    None   None   0     1    3                                         2   "      1% IMEO                                                                              "      10   10   10                                         3   "      1% GLYMO                                                                             "      4    10   10                                         4   "      1% VTEO                                                                              "      0     0    0                                         5   "      1% VTEO                                                                              0.1% by Wt.                                                                          1    10   10                                         6   "      1% VTMO                                                                              "      0    10   10                                         7   "      1% MEMO                                                                              "      3     6   10                                         8   26% by Wt..sup.(2)                                                                   None   None   0     2    5                                         9   "      1% IMEO                                                                              "      10   10   10                                         10  "      1% GLYMO                                                                             "      10   10   10                                         11  "      1% VTEO                                                                              "      0     0    0                                         12  "      1% VTEO                                                                              0.1% by Wt.                                                                          10   10   10                                         13  "      1% VTMO                                                                              "      10   10   10                                         14  "      1% MEMO                                                                              "      10   10   10                                         __________________________________________________________________________     .sup.(1) Shore A Hardness = 97                                                .sup.(2) Shore A Hardness = 79                                                IMEO = Imidazolylpropyltriethoxysilane                                        GLYMO = Glycidyloxypropyltrimethoxysilane                                     VTEO = Vinyltriethoxysilane                                                   VTMO = Vinyltrimethoxysilane                                                  MEMO = Methacryloxypropyltrimethoxysilane                                

EXAMPLES 15-22

The procedure of Examples 1-14 was followed, except that the autoclavestep was conducted at 12 bar and 140° C. for 3 hours:

    __________________________________________________________________________    Ex- Vinyl  Silane Dicumyl                                                                              Pummel Adhesion                                      ample                                                                             Acetate                                                                              % by   Per-   Va1ue at                                             No. Content                                                                              Weight oxide  -20° C.                                                                     +23° C.                                                                     +90° C.                             __________________________________________________________________________    15  26% by Wt..sup.(1)                                                                   None   None    0    2    5                                         16  "      1% IMEO                                                                              "      10   10   10                                         17  "      1% GLYM0                                                                             "      10   10   10                                         18  "      1% VTEO                                                                              0.1% by Wt.                                                                           3   10   10                                         19  45% by Wt..sup.(2)                                                                   None   None    0    5   10                                         20  "      1% IMEO                                                                              "      10   10   10                                         21  "      1% GLYMO                                                                             "      10   10   10                                         22  "      1% VTEO                                                                              0.1% by Wt.                                                                           0    5   10                                         __________________________________________________________________________     .sup.(1) Shore A Hardness = 79                                                .sup.(2) Shore A Hardness = 85                                                IMEO = Imidazolylpropyltriethoxysilane                                        GLYMO = Glycidyloxypropyltrimethoxysilane                                     VTEO = Vinyltriethoxysilane                                              

EXAMPLES 23-27

The process took place analogously to Examples 1-14, but using thefollowing films:

(1) Films of a copolymer of ethylene and acrylic acid butyl ester(commercially available under the name "Lupolen" A 2710 HX from BASF,Shore A hardness 87).

(2) Films of a quaternary polymer of ethylene, another olefin, acrylicacid, and acrylic acid esters (commercially available under the name"Lupolen" A 2910 MX, Shore A hardness 94).

    ______________________________________                                        Ex-             Silane                                                        ample           % by      Pummel Adhesion Value at                            No.   Copolymer Weight    -20° C.                                                                       +23° C.                                                                       +90° C.                        ______________________________________                                        23    A 2710 HX None       0      1      7                                    24    "         1% IMEO   10     10     10                                    25    A 2910 MX None      10     10     10                                    26    "         1% ATAO   10     10     10                                    27    "         5% ATAO    1      5      5                                    ______________________________________                                         IMEO = Imidazolylpropyltriethoxysilane                                        ATAO = Isobutyltrimethoxysilane                                          

EXAMPLES 28 and 29

In a supplement to Examples 15-17, silanes were used in varnishes ratherthan in a pure solvent:

With the use of a partially saponified copolymer of vinyl chloride andvinyl acetate with vinyl alcohol groups (obtainable commercially underthe name "Vinylite" VAGH from Union Carbide Corporation), 25% by weightof diisodecyl phthalate as the plasticizer, based on the copolymer, astabilizer system for the copolymer, and methyl isobutyl ketone as thesolvent, varnish number 1 was prepared. The varnish contained 10% byweight of a binder (=copolymer+plasticizer+stabilizer) and 1% by weightof γ-imidazolylpropyltriethoxysilane (IMEO).

Furthermore, varnish number 2 was prepared with the use of theabove-mentioned, plasticized, stabilized copolymer "Vinylite" VAGH andanother copolymer, plasticized and stabilized in the same way, of vinylchloride, vinyl acetate, and maleic acid (obtainable commercially underthe name "Hostaflex" M 133 from Hoechst AG.). The quantitative ratio ofthe two copolymers VAGH: M 133 was 24:1, and the binder proportion was15% by weight. The varnish contained furthermore 1% by weight ofγ-glycidyloxypropyltrimethoxysilane (GLYMO).

These varnishes were used to treat, by dipping, films having a thicknessof 0.4 mm. made of a copolymer of ethylene with 26% by weight vinylacetate. After evaporation of the solvents, the thus-treated films wereplaced between two glass plates. The sandwiches were passed through apair of rubber rolls for removal of air bubbles and then furtherprocessed in an autoclave at 12 bar and 140° C. for 3 hours, producingflawless composite glass. The film adhesion was determined according tothe pummel adhesion test method:

    __________________________________________________________________________    Ex-          Silane Pummel Adhesion                                           ample                                                                             Varnish  % by   Value at                                                  No. No.  with                                                                              Weight -20° C.                                                                      +23° C.                                                                     +90° C.                                 __________________________________________________________________________    28  1        1% IMEO                                                                              10    10   10                                             29  2        1% GLYMO                                                                             10    10   10                                             __________________________________________________________________________

EXAMPLE 30

A copolymer of ethylene and 26% by weight vinyl acetate was used toproduce films having a thickness of 0.4 mm. These films were treatedwith a 1% by weight solution of γ-imidazolylpropyltriethoxysilane (IMEO)in toluene as described in Example 16 and then processed into compositeglass.

Furthermore, films having a thickness of 0.4 mm. and made of plasticizedpolyvinyl butyral (PVB) with a good adhesion characteristic (structuralglass quality) was climatized to a moisture content of 0.45% by weightand likewise processed into composite glass.

Both types of composite glass were then subjected to a falling-ball testsimilar to DIN [German Industrial Standard] 52 306, at a temperature of+23° C. and at a temperature of -20° C. with the use of a steel ball of227 g. The results are listed in Table 1. As can be seen from Table 1,when using plasticizer-free films of a copolymer of ethylene and 26% byweight vinyl acetate, it is possible to produce composite glass which isespecially resistant to the effects of impacts under low temperatures,as compared to films made from plasticized polyvinyl butyral. Thefalling ball height without damage is approximately twice as high at atemperature of -20° C.

                                      TABLE 1                                     __________________________________________________________________________             0.4 mm.                                                                            Copolymer  0.4 mm.                                                                            PVB Film                                             Falling                                                                           Surface    Splinter                                                                           Surface    Splinter                                       Height                                                                            Crack      Weight                                                                             Crack      Weight                                    Temp.                                                                              (m.)                                                                              (cm.)                                                                              Penetration                                                                         (g.) (cm.)                                                                              Penetration                                                                         (g.)                                      __________________________________________________________________________    +23° C.                                                                     6   None None  0.2  --   --    --                                             7   2    "     3.3  --   --    --                                             8   5    "     2.2  --   --    --                                             8   2/1  "     1.2  --   --    --                                             8   7    "     7.9  None None  1.3                                            9   10   Yes   --   --   --    --                                             12  --   --    --    9/2 None  6.8                                            13  --   --    --   12/4 "     6.2                                            14  --   --    --   11   Yes   --                                             16  --   --    --   12/6/2                                                                             None  7.5                                       -20° C.                                                                     5   --   --    --   None None  0                                              6   None None  0.1  "    "     0.2                                            7   "    "     0.3  --   Yes   --                                             8   3    "     1.8  --   --    --                                             10  3/1  "     2.0  --   --    --                                             11  12/12/12                                                                           "     4.4  --   --    --                                             12  12/5 Yes   --   --   --    --                                        __________________________________________________________________________

EXAMPLES 31-39

Plasticized polyvinyl butyral film having a high glass adhesion (qualityfor structural glass, pummel adhesion value 10) was treated, by dipping,with solutions consisting of toluene as the solvent and various silanesin different concentrations. Thereafter, the solvent was removed byevaporation at room temperature. The differently treated films wereclimatized to a water content of 0.45%, placed between two glass plates,and heated so that a temperature of 90° C. could be measured on theglass surfaces. The warm sandwich was passed through a pair of rubberrolls to remove air bubbles. The thus-produced preliminary compositearticle was then treated in an autoclave at 12 bars and 140° C. for 3hours, whereby a flawless composite glass was produced. The glassadhesion of the films was determined at -20° C. according to the pummelmethod:

    ______________________________________                                                        Pummel                  Pummel                                Ex-   Silane    Adhesion Ex-   Silane   Adhesion                              ample % by      Value at ample & by     Value at                              No.   Weight    -20° C.                                                                         No.   Weight   -20° C.                        ______________________________________                                        31    0 ATAO    10       10    0.1 MEMO 4                                     32    0.5 ATAO  10       11    1 MEMO   0                                     33    1 ATAO    10       12    5 MEMO   0                                     34    2 ATAO    7        13    0.1 SIFO 1                                     35    3 ATAO    5        14    5 SIFO   0                                     36    5 ATAO    3        15    0.l GLFMO                                                                              3                                     37    5.5 ATAO  1        16    1 GLFMO  0                                     38    6 ATAO    1        17    0.l ACTMO                                                                              3                                     39    7 ATAO    1        18    1 ACTMO  1                                                              19    5 ACTMO  0                                     ______________________________________                                         ATAO = Isobutyltrimethoxysilane                                               MEMO = Methacryloxypropyltrimethoxysilane                                     SIFO = 2[Triethoxysilyl]ethylphosphonic acid diethyl ester                    GLFMO = 4[Methyl3(trimethoxysilyl)-propoxy1,3-dioxolane                       ACTMO = [1(Polyethylene/propylene                                             glycol)3-(trimethoxy-silyl)-propylacetate                                

EXAMPLES 40-47

A plasticized polyvinyl butyral film with high glass adhesion(structural glass quality, pummel adhesion value 10) was treated with asolution of 3.0 and 5.5% by weight, respectively, ofisobutyltrimethoxysilane (ATAO) in toluene; after evaporation of thesolvent to differing water contents, the silanized film was climatized.

The composite glass was produced as described in Examples 1-19. Forcomparison purposes, a composite glass was produced with an untreatedpolyvinyl butyral film of the same quality and the same water content.The results can be seen from the following table:

    ______________________________________                                                         Water      Pummel Adhesion                                   Ex-      ATAO    Content    Value at -20° C.                           ample    % by    % by       Untreated                                                                             Treated                                   No.      Wt.     Weight     Film    Film                                      ______________________________________                                        40       5.5     0.31       10      1                                         41       5.5     0.41       10      1                                         42       5.5     0.64        7      1                                         43       5.5     0.82        4      1                                         44       3.0     0.32       10      5                                         45       3.0     0.41       10      5                                         46       3.0     0.61        7      2                                         47       3.0     0.82        4      1                                         ______________________________________                                    

EXAMPLES 48-50

Examples 31-39 were repeated except that the solvents were petroleumether and xylene, instead of toluene, which were used for producing a 5%by weight solution with isobutyl trimethoxysilane (ATAO).

    ______________________________________                                                              Pummel Adhesion                                         Ex-                   Value at -20° C.                                 ample                 Untreated Treated                                       No.     Solvent       Film      Film                                          ______________________________________                                        48      Toluene       10        3                                             49      Petroleum     10        4                                                     ether                                                                 50      Xylene        10        4                                             ______________________________________                                    

Analogously to Examples 31-39, a plasticized polyvinyl butyral film witha controlled adhesion to glass was utilized (quality for windshields,pummel adhesion value 2) was utilized and treated as described inExamples 1-30, and then processed to obtain a composite glass:

    ______________________________________                                        Ex-                                                                           ample    Silane       Pummel Adhesion Value                                   No.      % by Weight  at -20° C.                                       ______________________________________                                        51       0       IMEO     2                                                   52       0.0005  IMEO     2                                                   53       0.001   IMEO     3                                                   54       0.002   IMEO     3                                                   55       0.004   IMEO     6                                                   56       0.006   IMEO     6                                                   57       0.008   IMEO     7                                                   58       0.01    IMEO     10                                                  59       0.02    IMEO     10                                                  60       0.03    IMEO     10                                                  61       0.04    IMEO     10                                                  62       0.001   AMEO     2                                                   63       0.005   AMEO     6                                                   64       0.01    AMEO     6                                                   65       0.05    AMEO     10                                                  66       0.006   GLYMO    3                                                   67       0.03    GLYMO    4                                                   68       0.09    GLYMO    5                                                   69       0.6     GLYMO    5                                                   ______________________________________                                         IMEO = lmidazolylpropyltriethoxysilane                                        AMEO = Aminopropyltriethoxysilane                                             GLYMO = Glycidyloxypropyltrimethoxysilane                                

EXAMPLES 70-73

A plasticized polyvinyl butyral film with controlled glass adhesion, asutilized in Examples 51-69 was treated with a solution of 0.01% byweight of γ-imidazolylpropyltriethoxysilane (IMEO) in toluene and, afterevaporation of the solvent, climatized to differing water contents. Thecomposite glass was produced as described in Examples 1-30:

    ______________________________________                                                         Pummel Adhesion Value                                                         at -20° C.                                            Example  Water Content Untreated Treated                                      No.      % by Weight   Film      Film                                         ______________________________________                                        70       0.31          3         10                                           71       0.41          3         10                                           72       0.64          3         10                                           73       0.82          2         10                                           ______________________________________                                    

EXAMPLES 74-79

Plasticized polyvinyl butyral film having a high glass adhesion (qualityfor structural glass, pummel adhesion value 10) was utilized for theproduction of composite safety glass, with the use of metalized glasses,wherein the metalized sides of the glass were placed facing thepolyvinyl butyral film, i.e. toward the inside. The polyvinyl butyralfilms had previously been treated with a solution of silane in tolueneand had been climatized to a water content of 0.45%.

    ______________________________________                                                           Pummel Adhesion                                                               Values at -20° C.                                   Example            Silane %  Untreated                                                                             Treated                                  No.    Glass Coating                                                                             by Weight Film    Film                                     ______________________________________                                        74     Auresin.sup.(R) 50/36                                                                     5 AMEO    1       7                                        75     Auresin.sup.(R) 55/42                                                                     5 AMEO    1       5                                        76     Metallic 50/47                                                                            5 AMEO    1       2                                        77     Auresin.sup.(R) 50/36                                                                     5 GLYMO   1       3                                        78     Auresin.sup.(R) 55/42                                                                     5 GLYMO   1       4                                        79     Metallic 50/47                                                                            5 GLYMO   1       3                                        ______________________________________                                         AMEO = Aminopropyltriethoxysilane                                             GLYMO = Glycidyloxypropyltrimethoxysilane                                

EXAMPLES 80-87

Plasticized polyvinyl butyral film having a high glass adhesion andsurface-coated glass were used for the production of a composite safetyglass, as described in Examples 74-79, but a silane-containing varnishwas employed. For this purpose, a solution was prepared from 2% byweight of plasticized polyvinyl butyral film and 1% by weight of silane.The solvent was a 1:4 mixture of dioxane and methyl isobutyl ketone. Thepolyvinyl butyral film (Examples 80-83) and/or the coated glass(Examples 84-87) were treated with this silane-containing varnish.Before the production of the composite article, the polyvinyl butyralfilm was climatized to a water content of 0.45%.

    ______________________________________                                        Ex-                         Pummel Adhes-                                     ample                       ion Value                                         No.   Glass Coating                                                                             Silane    at -20° C.                                 ______________________________________                                                                    Untreated                                                                              Treated                                                              Film     Film                                     80    Calorex .sup.(R)                                                                          IMEO      6        10                                       81    Parelio .sup.(R)                                                                          IMEO      6        10                                       82    Calorex .sup.(R)                                                                          GLYMO     6        10                                       83    Parelio .sup.(R)                                                                          GLYMO     6        10                                                                   Untreated                                                                              Treated                                                              Glass    Glass                                    84    Calorex .sup.(R)                                                                          IMEO      6        10                                       85    Parelio .sup.(R)                                                                          IMEO      6        10                                       86    Calorex .sup.(R)                                                                          GLYMO     6        10                                       87    Parelio .sup.(R)                                                                          GLYMO     6        10                                       ______________________________________                                         IMEO = lmidazolylpropyltriethoxysilane                                        GLYMO = Glycidyloxypropyltrimethoxysilane                                

EXAMPLES 88-102

A mixture of 32 parts by weight of methyl isobutyl ketone, 23 parts byweight of isopropanol, and 34.2 parts by weight of toluene is combinedwith 8 parts by weight of a partially saponified copolymer of vinylchloride and vinyl acetate with vinyl alcohol groups (commerciallyobtainable under the name of "Vinylite" VAGH from Union CarbideCorporation), 2 parts by weight of diisodecyl phthalate, 0.4 part byweight of a tin stabilizer (commercially available under the name of"Irgastab" 17M) and 0.4 part by weight of epoxidized soybean oil, thusforming a solution. The thus-produced primer is mixed with the amountsindicated in Table 1 of γ-imidazolylpropyltriethoxysilane (IMEO) andγ-aminopropyltriethoxysilane (AMEO) andγ-(β-aminoethyl)-aminopropyltrimethoxysilane (DAMO) andγ-glycidyloxypropyltrimethoxysilane (GLYMO), respective.

A plasticized film containing polyvinyl chloride is treated with thisvarnish by dipping, spraying, or printing, and the varnish solvent isthereafter removed by evaporation. The PVC films treated in this way arethen placed between silicate glass and the thus-produced sandwich ispassed in the cold state through a pair of rubber rolls to removeentrapped air and is then subjected to an autoclave treatment at 140° C.and under a pressure of 12 bar with a total running time of 11/2 hours.The thus-obtained composite glass is tested for film adhesion accordingto the pummel adhesion test method at -20° C. The results can be seenfrom Table 2.

                  TABLE 2                                                         ______________________________________                                        Ex-                                                                           ample     Silane      Pummel Adhesion Value                                   No.       % by Weight at -20° C.                                       ______________________________________                                        88        1% AMEO     10                                                      89        1% DAMO     10                                                      90        1% IMEO     10                                                      91        0.5% IMEO   10                                                      92        0.05% IMEO  10                                                      93        0.01% IMEO  10                                                      94        0.005% IMEO  6                                                      95        0.001% IMEO  4                                                      96        0.0005% IMEO                                                                               2                                                      97        1% GLYMO    10                                                      98        0.5% GLYMO  10                                                      99        0.1% GLYMO   6                                                      100       0.05% GLYMO  3                                                      101       0.01% GLYMO  1                                                      102       No Additive  0                                                      ______________________________________                                    

EXAMPLES 103-113

A mixture of 24 parts by weight of methyl isobutyl ketone, 43.5 parts byweight of xylene, and 24.8 parts by weight of cyclohexanone is combinedwith 3.41 parts by weight of a low-polymeric polymethyl methacrylateresin (commercially available under the name M 345 from Rohm), 1.46parts by weight of a copolymer of vinyl chloride, vinyl acetate, andmaleic acid (commercially available under the name "Hostaflex" M 133from Hoechst AG.), 2.63 parts by weight of dioctyl adipate, andrespectively 0.1 part by weight of the stabilizers mentioned in Examples1-15, thus forming a solution. The thus-obtained primer is mixed withthe amounts indicated in Table 3 ofβ-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane (ECHMO) andγ-glycidyloxypropyltrimethoxysilane (GLYMO). The further processingsteps took place analogously to Examples 88-102. The resultant adhesiontest data are set forth in Table 3 below.

                  TABLE 3                                                         ______________________________________                                        Ex-                                                                           ample     Silane      Pummel Adhesion Value                                   No.       % by Weight at -20° C.                                       ______________________________________                                        103       None         0                                                      104       0.2% ECHMO   2                                                      105       0.5% ECHMO  10                                                      106       0.8% ECHMO  10                                                      107       0.2% GLYMO   2                                                      108       0.5% GLYMO  10                                                      109       0.8% GLYMO  10                                                      ______________________________________                                    

For comparison purposes, the same primer was produced as set forth inExamples 103-109, except that it did not contain the copolymer of vinylchloride, vinyl acetate, and maleic acid. This primer was mixed with theamounts of GLYMO indicated in Table 3, and the resultant product wasfurther processed as set forth above. The results can be seen from Table4.

                  TABLE 4                                                         ______________________________________                                        Ex-                                                                           ample     GLYMO      Pummel Adhesion Value                                    No.       % by Weight                                                                              at -20° C.                                        ______________________________________                                        110       0.2        0                                                        111       0.5        0                                                        112       1.0        0                                                        113       2.0        0                                                        ______________________________________                                    

EXAMPLES 114-120

Example 106 was repeated, with the difference that the ratio ofpolymethyl methacrylate resin (PMMA): copolymer of vinyl chloride, vinylacetate, and maleic acid (VC/VAc/MA) was varied in that the proportionof the polymethyl methacrylate resin was increased. The correspondingamounts can be seen from Table 5. The further processing steps werecarried out analogously to Examples 103-109. The results can be seenfrom Table 5.

                  TABLE 5                                                         ______________________________________                                                                           Pummel                                     Ex-   Quantitative Ratio ECHMO     Adhesion                                   ample of the Polymers    % by      Value at                                   No.   PMMA       VC/VAc/MA   Weight  -20° C.                           ______________________________________                                        114   2.34       1           0.8     10                                       115   3.07       1           0.8     10                                       116   3.88       1           0.8     10                                       117   5.97       1           0.8     10                                       118   8.76       1           0.8      3                                       119   23.4       1           0.8      2                                       120   23.        1           None     0                                       ______________________________________                                    

We claim:
 1. A laminated safety glass consisting of(a) at least one silica glass sheet; (b) a plasticizer free soft film of a copolymer, said copolymer consisting essentially of ethylene and vinyl acetate, said copolymer having a vinyl acetate content of 8 to 45% by weight, said soft film having a Shore A hardness of 40 to 98, a number average of molecular weight determined in o-dichloro-benzene at 90° C. in a membrane osmometer between 20,000 and 100,000 melt flow index, as determined according to DIN 53 735, of between 0.1 and 20 g/10 minutes, and (c) a bonding agent consisting essentially of a functional silane, said functional silane being selected from the group consisting of a silicon-organofunctional silane of the formula ##STR6## wherein R is a hydrolyzable residue, R' is an alkyl residue of 1-18 carbon atoms; A is a bivalent alkylene residue of 1-10 carbon atoms which can be branched, and is a residue containing a functional group, which functional group is selected from the group consisting of ##STR7## halogen, NR² R³ and ##STR8## wherein R² is selected from the group consisting of H and an amino alkyl of 2-8 carbon atoms in the alkyl residue; and R³ is H and R² ; and R⁴ is selected from the group consisting of H, CH₃ and C₂ H₅ ; and n is 1 to 3 and p is 0 or 1, and a siliconfunctional silane of the formula

    R.sub.n.sup.1 --Si--R.sub.4-n

whereinR' is identical or different, saturated, unbranched or branched alkyl residues of 1-18 carbon atoms, R is selected from the group consisting of halogen, identical or different saturated alkoxy groups of 1-8 carbon atoms and an acyl residue linked to the Si atom via an oxygen atom, and wherein n is 1 to
 3. 2. A laminated safety glass according to claim 1 wherein said silane is a silicon organofunctional silane.
 3. A laminated safety glass according to claim 1, wherein said silane is a silicon functional silane.
 4. A laminated glass according to claim 1 wherein said plasticizer free soft film is disposed between a pair of silica glass sheets and laminated to said silica glass sheets by said functional silane.
 5. A laminated safety glass according to claim 2 wherein said silicon-organofunctional silane is present between the plasticizer free soft film and the silica glass sheet in an amount of 0.0001 to 5 weight percent.
 6. A laminated safety glass according to claim 2 wherein said silicon-organofunctional silane is present in an amount of 0.0005 to 2 weight percent.
 7. A laminated safety glass according to claim 1 wherein said silane is δ-glycidyloxypropyltrimethoxysilane.
 8. A laminated safety glass according to claim 1 wherein said silane is δ-imidozolylpropyltriethoxysilane.
 9. A laminated safety glass according to claim 1 wherein the functional silane is in a solution and the silane concentration in the solution is 0.0001 to 10 percent by weight.
 10. A laminated safety glass according to claim 1 wherein the functional silane is in a solution and the silane concentration in the solution is 0.0005 to 7.0 percent by weight.
 11. A laminated safety glass according to claim 1 wherein said silicon-function silane is present in an amount of 0.5 to 7 weight percent.
 12. A laminated safety glass according to claim 1 wherein said silicon-function silane is present in an amount of 1 to 5 weight percent.
 13. A laminated safety glass according to claim 1 wherein the functional silane is in a varnish and the silane concentration in the varnish is 0.0001 to 7 percent by weight.
 14. A laminated safety glass according to claim 1 wherein the silane is in a varnish and the silane concentration in the varnish is 0.0005 to 5 percent by weight.
 15. A laminated safety glass according to claim 1 wherein said silicon-organofunctional silane contains epoxy groups and said silane is contained in a varnish, the silane being present in an amount of 0.01 to 5 percent by weight.
 16. A laminated safety glass according to claim 1 wherein said silicon-organofunctional silane contains epoxy groups, and said silane is contained in a varnish, the silane being present in an amount of 0.01 to 2 percent by weight.
 17. A laminated safety glass according to claim 1 wherein said silicon-organofunctional silane contains amino groups, and said silane is contained in a varnish, the silane being present in an amount of 0.0001 to 2 percent by weight.
 18. A laminated safety glass according to claim 1 wherein said silicon-organofunctional silane contains amino groups, and said silane is contained in a varnish, the silane being present in an amount of 0.0005 to 1 percent by weight. 